Acidic post-sputter wash for magnetic recording media
View Patent ↗A recording medium having an outer surface relatively free of magnetic particulates is achievable by, after forming a magnetic recording layer with which magnetic contamination is associated, removing magnetic contamination from the medium by immersing the medium in an acidic water solution. For example, a post-sputter wash process utilizing a mildly acidic water solution having a pH less than around 5 may remove cobalt particle contaminants from the surface of the medium. The water solution may be acidized by introducing into deionized water a pre-diluted strong acid such as nitric acid or a weak acid such as carbonic acid.
1. A method of manufacturing a magnetic recording medium, the method comprising:
forming one or more magnetic recording layer over a substrate to form a magnetic recording medium; and
removing, from an outer surface of said magnetic recording medium, magnetic contamination associated with said one or more magnetic recording layer by immersing said magnetic recording medium in an acidic water solution.
2. The method of claim 1 , wherein said forming includes performing a sputter deposition process, and wherein said removing includes removing cobalt particle contaminants from said outer surface of said magnetic recording medium.
3. The method of claim 1 , wherein said immersing includes immersing said magnetic recording medium in a water solution having a pH less than around 5.
4. The method of claim 1 , further comprising:
prior to said immersing, introducing a mild acid into a deionized water source, wherein said mild acid comprises around a 2% or lower pre-diluted nitric acid.
5. The method of claim 1 , further comprising:
prior to said immersing, introducing a mild acid into a deionized water source, wherein said mild acid comprises a carbonic acid.
6. The method of claim 1 , further comprising:
after removing said magnetic contamination from said outer surface of said magnetic recording medium, removing residual acid from said outer surface of said magnetic recording medium by rinsing said magnetic recording medium in deionized water.
7. The method of claim 6 , further comprising:
exposing said magnetic recording medium to isopropyl alcohol.
8. The method of claim 1 , wherein said immersing comprises immersing in a first acidic water solution, the method further comprising:
further removing magnetic contamination from said outer surface of said magnetic recording medium by immersing said magnetic recording medium in a second acidic water solution after immersing in said first acidic water solution.
9. A magnetic recording medium prepared by a process comprising:
forming one or more magnetic recording layer over a substrate;
forming an overcoat over said one or more magnetic recording layer, thereby forming an unfinished magnetic recording medium; and
removing, from an outer surface of said unfinished magnetic recording medium, magnetic contamination associated with said one or more magnetic recording layer by immersing said magnetic recording medium in an acidic water solution, thereby forming a finished magnetic recording medium;
wherein said outer surface of said finished magnetic recording medium is substantially free of magnetic particulates on said overcoat.
10. The magnetic recording medium of claim 9 , wherein said forming one or more magnetic recording layer comprises performing a sputter deposition process, and wherein said removing includes removing cobalt particle contaminants from said outer surface of said magnetic recording medium.
11. The magnetic recording medium of claim 9 , wherein said immersing includes immersing said magnetic recording medium in a water solution having a pH less than around 5.
12. The magnetic recording medium of claim 9 , wherein said acidic water solution comprises a solution of around 2% or lower pre-diluted nitric acid with deionized water.
13. The magnetic recording medium of claim 9 , wherein said acidic water solution comprises a solution of carbonic acid with deionized water.
14. The magnetic recording medium of claim 9 , the preparation process further comprising:
exposing said finished magnetic recording medium to isopropyl alcohol.
15. A data storage device comprising:
a magnetic recording medium rotatably mounted on a spindle, said magnetic recording medium prepared by a process comprising:
forming one or more magnetic recording layer over a substrate;
forming an overcoat over said one or more magnetic recording layer, thereby forming an unfinished magnetic recording medium; and
removing, from an outer surface of said unfinished magnetic recording medium, magnetic contamination associated with said one or more magnetic recording layer by immersing said magnetic recording medium in an acidic water solution, thereby forming a finished magnetic recording medium;
wherein said outer surface of said finished magnetic recording medium is substantially free of magnetic particulates on said overcoat;
a read-write head slider configured to read from and to write to said magnetic recording medium; and
a voice coil actuator configured to move said head slider to access portions of said magnetic recording medium.
16. The data storage device of claim 15 , wherein said forming one or more magnetic recording layer comprises performing a sputter deposition process, and wherein said removing includes removing cobalt particle contaminants from said outer surface of said magnetic recording medium.
17. The data storage device of claim 15 , wherein said immersing includes immersing said magnetic recording medium in a water solution having a pH less than around 5.
18. The data storage device of claim 15 , wherein said acidic water solution comprises a solution of around 2% or lower pre-diluted nitric acid with deionized water.
19. The data storage device of claim 15 , wherein said acidic water solution comprises a solution of carbonic acid with deionized water.
20. The data storage device of claim 15 , the preparation process further comprising:
after removing said magnetic contamination from said outer surface of said magnetic recording medium, removing residual acid from said outer surface of said magnetic recording medium by rinsing said magnetic recording medium in deionized water; and
exposing said magnetic recording medium to isopropyl alcohol.